Postgresql存储过程中的结果集Llike Java

Question

hi is there any way to do the following java code in postgresql stored procedure

String sqlQuery = "SELECT uid, name, duration from EVENTS";

    ResultSet rs = stmt.executeQuery(sqlQuery);

    while (rs.next()) {
       String name = rs.getString(2);
     }

i need the same in the postgresql stored procedure?

Answer 1

Per the PL/PgSQL documentation you use a LOOP over a query for that.

DO
$$
DECLARE
    myresult record;
BEGIN
    FOR myresult IN SELECT uid, name, duration FROM events
    LOOP
        RAISE NOTICE 'Name is %',myresult.name;
    END LOOP;
END;
$$ LANGUAGE plpgsql;

However, use of loops is very often a sign you're just not using SQL properly. It's highly likely that proper use of WITH queries (common table expressions) and a bit of thought will get you a pure SQL solution that'll generally perform a LOT better.

In future, please give your PostgreSQL version and explain a little about what you're actually trying to accomplish. The code you show is completely useless, it does nothing. So it's obviously not what you really want to do, but you've told us nothing about that. Quite often the solution you think you need (looping, say) isn't the solution you really need.